/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Creative Labs, Inc.
* Lee Revell <rlrevell@joe-job.com>
* Routines for control of EMU10K1 chips - voice manager
*
* Rewrote voice allocator for multichannel support - rlrevell 12/2004
*
* BUGS:
* --
*
* TODO:
* --
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sound/driver.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/emu10k1.h>
/* Previously the voice allocator started at 0 every time. The new voice
* allocator uses a round robin scheme. The next free voice is tracked in
* the card record and each allocation begins where the last left off. The
* hardware requires stereo interleaved voices be aligned to an even/odd
* boundary. For multichannel voice allocation we ensure than the block of
* voices does not cross the 32 voice boundary. This simplifies the
* multichannel support and ensures we can use a single write to the
* (set|clear)_loop_stop registers. Otherwise (for example) the voices would
* get out of sync when pausing/resuming a stream.
* --rlrevell
*/
static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
struct snd_emu10k1_voice **rvoice)
{
struct snd_emu10k1_voice *voice;
int i, j, k, first_voice, last_voice, skip;
*rvoice = NULL;
first_voice = last_voice = 0;
for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) {
// printk("i %d j %d next free %d!\n", i, j, emu->next_free_voice);
i %= NUM_G;
/* stereo voices must be even/odd */
if ((number == 2) && (i % 2)) {
i++;
continue;
}
skip = 0;
for (k = 0; k < number; k++) {
voice = &emu->voices[(i+k) % NUM_G];
if (voice->use) {
skip = 1;
break;
}
}
if (!skip) {
// printk("allocated voice %d\n", i);
first_voice = i;
last_voice = (i + number) % NUM_G;
emu->next_free_voice = last_voice;
break;
}
}
if (first_voice == last_voice)
return -ENOMEM;
for (i = 0; i < number; i++) {
voice = &emu->voices[(first_voice + i) % NUM_G];
// printk("voice alloc - %i, %i of %i\n", voice->number, idx-first_voice+1, number);
voice->use = 1;
switch (type) {
case EMU10K1_PCM:
voice->pcm = 1;
break;
case EMU10K1_SYNTH:
voice->synth = 1;
break;
case EMU10K1_MIDI:
voice->midi = 1;
break;
case EMU10K1_EFX:
voice->efx = 1;
break;
}
}
*rvoice = &emu->voices[first_voice];
return 0;
}
int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
struct snd_emu10k1_voice **rvoice)
{
unsigned long flags;
int result;
snd_assert(rvoice != NULL, return -EINVAL);
snd_assert(number, return -EINVAL);
spin_lock_irqsave(&emu->voice_lock, flags);
for (;;) {
result = voice_alloc(emu, type, number, rvoice);
if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
break;
/* free a voice from synth */
if (emu->get_synth_voice) {
result = emu->get_synth_voice(emu);
if (result >= 0) {
struct snd_emu10k1_voice *pvoice = &emu->voices[result];
pvoice->interrupt = NULL;
pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
pvoice->epcm = NULL;
}
}
if (result < 0)
break;
}
spin_unlock_irqrestore(&emu->voice_lock, flags);
return result;
}
EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
struct snd_emu10k1_voice *pvoice)
{
unsigned long flags;
snd_assert(pvoice != NULL, return -EINVAL);
spin_lock_irqsave(&emu->voice_lock, flags);
pvoice->interrupt = NULL;
pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
pvoice->epcm = NULL;
snd_emu10k1_voice_init(emu, pvoice->number);
spin_unlock_irqrestore(&emu->voice_lock, flags);
return 0;
}
EXPORT_SYMBOL(snd_emu10k1_voice_free);
